1. Field of the Invention
The present invention relates to a flexible multilayer substrate.
2. Description of the Related Art
A flexible multilayer substrate can be produced by laminating resin layers. In some cases, such a flexible multilayer substrate is mounted in a state of being flexed to a certain side. Depending on use, the flexible multilayer substrate may be used in the state of being flexed at the time of mounting, or may be flexed repeatedly during use even if the substrate is not originally flexed at the time of mounting.
An example of a flexible substrate flexed to the same side is disclosed in Japanese Patent Laying-Open No. 2007-201263.
When the flexible multilayer substrate is used in the flexed state or is flexed repeatedly during use, there is a problem of separation at a joint plane of via conductors or resin layers in the flexible multilayer substrate.